Processes for the desulfurization of gas (natural gas, CO.sub.2 gas mixtures, etc.), crude oil and water produced from hydrocarbon reservoirs after separating these phases have been long known. The gas desulfurization processes usually apply absorption, with or without chemical reaction, or adsorption followed by sulfur recovery from H.sub.2 S set free during solvent or adsorbent regeneration, by the Claus process, or direct conversion by which the H.sub.2 S is retained from the gas and simultaneously oxidized to sulfur by an oxidizing agent dissolved in an organic solvent.
For the desulfurization of crude oils hydrogenation processes and conversion of sulfur compounds to H.sub.2 S gas are used, the H.sub.2 S gas being then removed by one of the above processes.
Water desulfurization is achieved using alkaline solutions to neutralize H.sub.2 S, or solutions containing ions that retain H.sub.2 S as insoluble (precipitated) sulphides.
The drawbacks of these processes are such that they are applied after phase separation (gas, crude and water) causing considerable corrosion of pipelines and of phase separators. They cannot be applied to "rich" gas (containing more than 20 g/Nm.sup.3 of propane plus) and can be only selectively applied for certain H.sub.2 S concentration ranges, in addition large size facilities made of non-corrosive materials are required with high energy consumption and generally expensive chemicals.
The installations used by the above-mentioned desulfurization processes involve either absorption columns for H.sub.2 S and/or other sulfur compounds of the gas, or hydrogenation columns for crude distillates (light fractions), previously vaporized, with the thus formed H.sub.2 S being removed into an absorption column or treaters, in the case of water desulfurization, where alkaline or cations containing solutions react with H.sub.2 S, resulting in a sludge, that is removed by settling.
The disadvantages of these installations are such that for high gas rates relatively large size absorption columns are required and the materials they are made from are expensive because of the highly corrosive environment.